112,616 research outputs found
Unusual microstructure and mechanical properties of egg case of the bolas spider Mastophora corpulenta Banks (Araneae, Araneidae)
No full textSustainable and very-low-temperature wet-chemistry routes for the synthesis of crystalline inorganic nanostructures
No full textIn this chapter, selected low (T < 200 °C)-temperature wet-chemistry
routes for the synthesis of crystalline inorganic compounds are described and
reviewed, outlining their main features and application fi elds. In particular, the chosen
approaches are hydro/solvothermal synthesis, template-assisted approaches,
nucleation and growth in solution/suspension, microemulsion and miniemulsion.
The described synthetic strategies have been selected since all of them, once optimized
the experimental set-up and conditions, comply with the paradigms of green
chemistry, being based on low (or even room) temperature of processing, on low
chemical consumption (they are all bottom-up approach), in many cases having water
as solvent or dispersing medium. In this regard, environmentally friendly methodologies
for the controlled synthesis of inorganic nanostructures represent a stimulating
research playground, since the use of environmentally friendly, green, cost-effective
and technically sound approaches to inorganic crystalline nanostructures does not
necessarily imply to sacrifi ce the sample crystallinity, purity, and monodispersity
Chemical functionalization of inner walls of carbon nanotubes with long-chain aliphatic amines
No full textSynthesis of carbon nanotubes (CNTs) using porous anodic alumina membrane (PA) as template and the chemical functionalization of their inner walls is presented. The CNT were prepared by catalyst-free process using the pyrolysis of liquid aerosol of toluene: ethanol (1:1 v/v). The surface modification of the inner surface walls of CNT was performed using the gas phase synthesis by aliphatic amines (1,8-diaminooctane, DO). SEM, TEM and XPS analysis confirmed the morphology of prepared CNT inside of PA pores and their successful functionalization by amino groups. The presence and growth of interesting carbon nanoparticle inside CNT was observed during amination process. We hypothesized their origin as nanodiamonds formed as a result of the heat treatment in the presence of air that support etching mechanism and defects formation which acts as a diamond growth sites.Tariq Altalhi, Elena V. Basiuk, Juan Rizo, Vladimir A. Basiuk, Milena Ginic-Markovic, Stephen Clarke and Dusan Losi
author-bios-SRD-19-0063.R1 – Supplemental material for The Network Structure of Police Misconduct
No full textSupplemental material, author-bios-SRD-19-0063.R1 for The Network Structure of Police Misconduct by George Wood, Daria Roithmayr and Andrew V. Papachristos in Socius</p
Solvent-free covalent functionalization of multi-walled carbon nanotubes and nanodiamond with diamines: Looking for cross-linking effects
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Towards self-consistent plasma modelisation in presence of neoclassical tearing mode and sawteeth: effects on transport coefficients
No full textThe neoclassical tearing modes (NTM) increase the effective heat and particle radial transport inside the plasma, leading to a flattening of the electron and ion temperature and density profiles at a given location depending on the safety factor q rational surface (Hegna and Callen 1997 Phys. Plasmas 4 2940). In burning plasma such as in ITER, this NTM-induced increased transport could reduce significantly the fusion performance and even lead to a disruption. Validating models describing the NTM-induced transport in present experiment is thus important to help quantifying this effect on future devices. In this work, we apply an NTM model to an integrated simulation of current, heat and particle transport on JET discharges using the European transport simulator. In this model, the heat and particle radial transport coefficients are modified by a Gaussian function locally centered at the NTM position and characterized by a full width proportional to the island size through a constant parameter adapted to obtain the best simulations of experimental profiles. In the simulation, the NTM model is turned on at the same time as the mode is triggered in the experiment. The island evolution is itself determined by the modified Rutherford equation, using self-consistent plasma parameters determined by the transport evolution. The achieved simulation reproduces the experimental measurements within the error bars, before and during the NTM. A small discrepancy is observed on the radial location of the island due to a shift of the position of the computed q = 3/2 surface compared to the experimental one. To explain such small shift (up to about 12% with respect to the position observed from the experimental electron temperature profiles), sensitivity studies of the NTM location as a function of the initialization parameters are presented. First results validate both the transport model and the transport modification calculated by the NTM model
Solvent-free covalent functionalization of multi-walled carbon nanotubes and nanodiamond with diamines: Looking for cross-linking effects
No full textThe covalent functionalization of carbon nanomaterials with diamines is a way to enhance the mechanical strength of nanocomposites due to cross-linking effects, to form complex networks for nanotube-based electronic circuits, as well as is important for a number of biomedical applications. The main goal of the present work was to covalently functionalize pristine multi-walled carbon nanotubes and nanodiamond with three aliphatic diamines (1,8-diaminooctane, 1,10-diaminodecane and 1,12-diaminododecane) and one aromatic diamine (1,5-diaminonaphthalene), by employing a simple one-step solvent-free methodology, which is based on thermal instead of chemical activation. We looked for experimental evidences of cross-linking effects in the carbon nanomaterials synthesized by using solubility/dispersibility tests, atomic force microscopy, scanning and transmission electron microscopy, as well as Fourier-transform infrared spectroscopy and thermogravimetric analysis for additional characterization
Solvent-free functionalization of carbon nanotube buckypaper with amines
No full texttWe demonstrate the possibility of fast and efficient solvent-free functionalization of buckypaper(BP) mats prefabricated from oxidized multiwalled carbon nanotubes (MWCNTs-ox), by using threerepresentative amines of different structure: one monofunctional aliphatic amine, octadecylamine(ODA), one monofunctional aromatic amine, 1-aminopyrene (AP), and one aromatic diamine, 1,5-diaminonaphthalene (DAN). The functionalization procedure, which relies on the formation of amidebonds with carboxylic groups of MWCNTs-ox, is performed at 150–180◦C under reduced pressure andtakes about 4 h including auxiliary degassing. The amine-treated BP samples (BP-ODA, BP-AP and BP-DAN, respectively) were characterized by means of a variety of analytical techniques such as Fourier-transforminfrared and Raman spectroscopy, thermogravimetric and differential thermal analysis, scanning andtransmission electron microscopy, scanning helium ion microscopy, and atomic force microscopy. Thehighest amine content was found for BP-ODA, and the lowest one was observed for BP-DAN, with a possi-ble contribution of non-covalently bonded amine molecules in all three cases. Despite of some differencesin spectral and morphological characteristics for amine-functionalized BP samples, they have in commona dramatically increased stability in water as compared to pristine BP and, on the other hand, a relativelyinvariable electrical conductivity
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